xref: /openbmc/linux/drivers/media/rc/serial_ir.c (revision b78412b8)
1 /*
2  * serial_ir.c
3  *
4  * serial_ir - Device driver that records pulse- and pause-lengths
5  *	       (space-lengths) between DDCD event on a serial port.
6  *
7  * Copyright (C) 1996,97 Ralph Metzler <rjkm@thp.uni-koeln.de>
8  * Copyright (C) 1998 Trent Piepho <xyzzy@u.washington.edu>
9  * Copyright (C) 1998 Ben Pfaff <blp@gnu.org>
10  * Copyright (C) 1999 Christoph Bartelmus <lirc@bartelmus.de>
11  * Copyright (C) 2007 Andrei Tanas <andrei@tanas.ca> (suspend/resume support)
12  * Copyright (C) 2016 Sean Young <sean@mess.org> (port to rc-core)
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License as published by
15  *  the Free Software Foundation; either version 2 of the License, or
16  *  (at your option) any later version.
17  *
18  *  This program is distributed in the hope that it will be useful,
19  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  *  GNU General Public License for more details.
22  */
23 
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/interrupt.h>
29 #include <linux/kernel.h>
30 #include <linux/serial_reg.h>
31 #include <linux/types.h>
32 #include <linux/delay.h>
33 #include <linux/platform_device.h>
34 #include <linux/spinlock.h>
35 #include <media/rc-core.h>
36 
37 struct serial_ir_hw {
38 	int signal_pin;
39 	int signal_pin_change;
40 	u8 on;
41 	u8 off;
42 	unsigned set_send_carrier:1;
43 	unsigned set_duty_cycle:1;
44 	void (*send_pulse)(unsigned int length, ktime_t edge);
45 	void (*send_space)(void);
46 	spinlock_t lock;
47 };
48 
49 #define IR_HOMEBREW	0
50 #define IR_IRDEO	1
51 #define IR_IRDEO_REMOTE	2
52 #define IR_ANIMAX	3
53 #define IR_IGOR		4
54 
55 /* module parameters */
56 static int type;
57 static int io;
58 static int irq;
59 static ulong iommap;
60 static int ioshift;
61 static bool softcarrier = true;
62 static bool share_irq;
63 static int sense = -1;	/* -1 = auto, 0 = active high, 1 = active low */
64 static bool txsense;	/* 0 = active high, 1 = active low */
65 
66 /* forward declarations */
67 static void send_pulse_irdeo(unsigned int length, ktime_t edge);
68 static void send_space_irdeo(void);
69 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
70 static void send_pulse_homebrew(unsigned int length, ktime_t edge);
71 static void send_space_homebrew(void);
72 #endif
73 
74 static struct serial_ir_hw hardware[] = {
75 	[IR_HOMEBREW] = {
76 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_HOMEBREW].lock),
77 		.signal_pin	   = UART_MSR_DCD,
78 		.signal_pin_change = UART_MSR_DDCD,
79 		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
80 		.off = (UART_MCR_RTS | UART_MCR_OUT2),
81 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
82 		.send_pulse = send_pulse_homebrew,
83 		.send_space = send_space_homebrew,
84 		.set_send_carrier = true,
85 		.set_duty_cycle = true,
86 #endif
87 	},
88 
89 	[IR_IRDEO] = {
90 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO].lock),
91 		.signal_pin	   = UART_MSR_DSR,
92 		.signal_pin_change = UART_MSR_DDSR,
93 		.on  = UART_MCR_OUT2,
94 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
95 		.send_pulse = send_pulse_irdeo,
96 		.send_space = send_space_irdeo,
97 		.set_duty_cycle = true,
98 	},
99 
100 	[IR_IRDEO_REMOTE] = {
101 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IRDEO_REMOTE].lock),
102 		.signal_pin	   = UART_MSR_DSR,
103 		.signal_pin_change = UART_MSR_DDSR,
104 		.on  = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
105 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
106 		.send_pulse = send_pulse_irdeo,
107 		.send_space = send_space_irdeo,
108 		.set_duty_cycle = true,
109 	},
110 
111 	[IR_ANIMAX] = {
112 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_ANIMAX].lock),
113 		.signal_pin	   = UART_MSR_DCD,
114 		.signal_pin_change = UART_MSR_DDCD,
115 		.on  = 0,
116 		.off = (UART_MCR_RTS | UART_MCR_DTR | UART_MCR_OUT2),
117 	},
118 
119 	[IR_IGOR] = {
120 		.lock = __SPIN_LOCK_UNLOCKED(hardware[IR_IGOR].lock),
121 		.signal_pin	   = UART_MSR_DSR,
122 		.signal_pin_change = UART_MSR_DDSR,
123 		.on  = (UART_MCR_RTS | UART_MCR_OUT2 | UART_MCR_DTR),
124 		.off = (UART_MCR_RTS | UART_MCR_OUT2),
125 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
126 		.send_pulse = send_pulse_homebrew,
127 		.send_space = send_space_homebrew,
128 		.set_send_carrier = true,
129 		.set_duty_cycle = true,
130 #endif
131 	},
132 };
133 
134 #define RS_ISR_PASS_LIMIT 256
135 
136 struct serial_ir {
137 	ktime_t lastkt;
138 	struct rc_dev *rcdev;
139 	struct platform_device *pdev;
140 	struct timer_list timeout_timer;
141 
142 	unsigned int carrier;
143 	unsigned int duty_cycle;
144 };
145 
146 static struct serial_ir serial_ir;
147 
148 /* fetch serial input packet (1 byte) from register offset */
149 static u8 sinp(int offset)
150 {
151 	if (iommap)
152 		/* the register is memory-mapped */
153 		offset <<= ioshift;
154 
155 	return inb(io + offset);
156 }
157 
158 /* write serial output packet (1 byte) of value to register offset */
159 static void soutp(int offset, u8 value)
160 {
161 	if (iommap)
162 		/* the register is memory-mapped */
163 		offset <<= ioshift;
164 
165 	outb(value, io + offset);
166 }
167 
168 static void on(void)
169 {
170 	if (txsense)
171 		soutp(UART_MCR, hardware[type].off);
172 	else
173 		soutp(UART_MCR, hardware[type].on);
174 }
175 
176 static void off(void)
177 {
178 	if (txsense)
179 		soutp(UART_MCR, hardware[type].on);
180 	else
181 		soutp(UART_MCR, hardware[type].off);
182 }
183 
184 static void send_pulse_irdeo(unsigned int length, ktime_t target)
185 {
186 	long rawbits;
187 	int i;
188 	unsigned char output;
189 	unsigned char chunk, shifted;
190 
191 	/* how many bits have to be sent ? */
192 	rawbits = length * 1152 / 10000;
193 	if (serial_ir.duty_cycle > 50)
194 		chunk = 3;
195 	else
196 		chunk = 1;
197 	for (i = 0, output = 0x7f; rawbits > 0; rawbits -= 3) {
198 		shifted = chunk << (i * 3);
199 		shifted >>= 1;
200 		output &= (~shifted);
201 		i++;
202 		if (i == 3) {
203 			soutp(UART_TX, output);
204 			while (!(sinp(UART_LSR) & UART_LSR_THRE))
205 				;
206 			output = 0x7f;
207 			i = 0;
208 		}
209 	}
210 	if (i != 0) {
211 		soutp(UART_TX, output);
212 		while (!(sinp(UART_LSR) & UART_LSR_TEMT))
213 			;
214 	}
215 }
216 
217 static void send_space_irdeo(void)
218 {
219 }
220 
221 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
222 static void send_pulse_homebrew_softcarrier(unsigned int length, ktime_t edge)
223 {
224 	ktime_t now, target = ktime_add_us(edge, length);
225 	/*
226 	 * delta should never exceed 4 seconds and on m68k
227 	 * ndelay(s64) does not compile; so use s32 rather than s64.
228 	 */
229 	s32 delta;
230 	unsigned int pulse, space;
231 
232 	/* Ensure the dividend fits into 32 bit */
233 	pulse = DIV_ROUND_CLOSEST(serial_ir.duty_cycle * (NSEC_PER_SEC / 100),
234 				  serial_ir.carrier);
235 	space = DIV_ROUND_CLOSEST((100 - serial_ir.duty_cycle) *
236 				  (NSEC_PER_SEC / 100), serial_ir.carrier);
237 
238 	for (;;) {
239 		now = ktime_get();
240 		if (ktime_compare(now, target) >= 0)
241 			break;
242 		on();
243 		edge = ktime_add_ns(edge, pulse);
244 		delta = ktime_to_ns(ktime_sub(edge, now));
245 		if (delta > 0)
246 			ndelay(delta);
247 		now = ktime_get();
248 		off();
249 		if (ktime_compare(now, target) >= 0)
250 			break;
251 		edge = ktime_add_ns(edge, space);
252 		delta = ktime_to_ns(ktime_sub(edge, now));
253 		if (delta > 0)
254 			ndelay(delta);
255 	}
256 }
257 
258 static void send_pulse_homebrew(unsigned int length, ktime_t edge)
259 {
260 	if (softcarrier)
261 		send_pulse_homebrew_softcarrier(length, edge);
262 	else
263 		on();
264 }
265 
266 static void send_space_homebrew(void)
267 {
268 	off();
269 }
270 #endif
271 
272 static void frbwrite(unsigned int l, bool is_pulse)
273 {
274 	/* simple noise filter */
275 	static unsigned int ptr, pulse, space;
276 	DEFINE_IR_RAW_EVENT(ev);
277 
278 	if (ptr > 0 && is_pulse) {
279 		pulse += l;
280 		if (pulse > 250000) {
281 			ev.duration = space;
282 			ev.pulse = false;
283 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
284 			ev.duration = pulse;
285 			ev.pulse = true;
286 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
287 			ptr = 0;
288 			pulse = 0;
289 		}
290 		return;
291 	}
292 	if (!is_pulse) {
293 		if (ptr == 0) {
294 			if (l > 20000000) {
295 				space = l;
296 				ptr++;
297 				return;
298 			}
299 		} else {
300 			if (l > 20000000) {
301 				space += pulse;
302 				if (space > IR_MAX_DURATION)
303 					space = IR_MAX_DURATION;
304 				space += l;
305 				if (space > IR_MAX_DURATION)
306 					space = IR_MAX_DURATION;
307 				pulse = 0;
308 				return;
309 			}
310 
311 			ev.duration = space;
312 			ev.pulse = false;
313 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
314 			ev.duration = pulse;
315 			ev.pulse = true;
316 			ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
317 			ptr = 0;
318 			pulse = 0;
319 		}
320 	}
321 
322 	ev.duration = l;
323 	ev.pulse = is_pulse;
324 	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
325 }
326 
327 static irqreturn_t serial_ir_irq_handler(int i, void *blah)
328 {
329 	ktime_t kt;
330 	int counter, dcd;
331 	u8 status;
332 	ktime_t delkt;
333 	unsigned int data;
334 	static int last_dcd = -1;
335 
336 	if ((sinp(UART_IIR) & UART_IIR_NO_INT)) {
337 		/* not our interrupt */
338 		return IRQ_NONE;
339 	}
340 
341 	counter = 0;
342 	do {
343 		counter++;
344 		status = sinp(UART_MSR);
345 		if (counter > RS_ISR_PASS_LIMIT) {
346 			dev_err(&serial_ir.pdev->dev, "Trapped in interrupt");
347 			break;
348 		}
349 		if ((status & hardware[type].signal_pin_change) &&
350 		    sense != -1) {
351 			/* get current time */
352 			kt = ktime_get();
353 
354 			/*
355 			 * The driver needs to know if your receiver is
356 			 * active high or active low, or the space/pulse
357 			 * sense could be inverted.
358 			 */
359 
360 			/* calc time since last interrupt in nanoseconds */
361 			dcd = (status & hardware[type].signal_pin) ? 1 : 0;
362 
363 			if (dcd == last_dcd) {
364 				dev_err(&serial_ir.pdev->dev,
365 					"ignoring spike: %d %d %lldns %lldns\n",
366 					dcd, sense, ktime_to_ns(kt),
367 					ktime_to_ns(serial_ir.lastkt));
368 				continue;
369 			}
370 
371 			delkt = ktime_sub(kt, serial_ir.lastkt);
372 			if (ktime_compare(delkt, ktime_set(15, 0)) > 0) {
373 				data = IR_MAX_DURATION; /* really long time */
374 				if (!(dcd ^ sense)) {
375 					/* sanity check */
376 					dev_err(&serial_ir.pdev->dev,
377 						"dcd unexpected: %d %d %lldns %lldns\n",
378 						dcd, sense, ktime_to_ns(kt),
379 						ktime_to_ns(serial_ir.lastkt));
380 					/*
381 					 * detecting pulse while this
382 					 * MUST be a space!
383 					 */
384 					sense = sense ? 0 : 1;
385 				}
386 			} else {
387 				data = ktime_to_ns(delkt);
388 			}
389 			frbwrite(data, !(dcd ^ sense));
390 			serial_ir.lastkt = kt;
391 			last_dcd = dcd;
392 		}
393 	} while (!(sinp(UART_IIR) & UART_IIR_NO_INT)); /* still pending ? */
394 
395 	mod_timer(&serial_ir.timeout_timer,
396 		  jiffies + nsecs_to_jiffies(serial_ir.rcdev->timeout));
397 
398 	ir_raw_event_handle(serial_ir.rcdev);
399 
400 	return IRQ_HANDLED;
401 }
402 
403 static int hardware_init_port(void)
404 {
405 	u8 scratch, scratch2, scratch3;
406 
407 	/*
408 	 * This is a simple port existence test, borrowed from the autoconfig
409 	 * function in drivers/tty/serial/8250/8250_port.c
410 	 */
411 	scratch = sinp(UART_IER);
412 	soutp(UART_IER, 0);
413 #ifdef __i386__
414 	outb(0xff, 0x080);
415 #endif
416 	scratch2 = sinp(UART_IER) & 0x0f;
417 	soutp(UART_IER, 0x0f);
418 #ifdef __i386__
419 	outb(0x00, 0x080);
420 #endif
421 	scratch3 = sinp(UART_IER) & 0x0f;
422 	soutp(UART_IER, scratch);
423 	if (scratch2 != 0 || scratch3 != 0x0f) {
424 		/* we fail, there's nothing here */
425 		pr_err("port existence test failed, cannot continue\n");
426 		return -ENODEV;
427 	}
428 
429 	/* Set DLAB 0. */
430 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
431 
432 	/* First of all, disable all interrupts */
433 	soutp(UART_IER, sinp(UART_IER) &
434 	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
435 
436 	/* Clear registers. */
437 	sinp(UART_LSR);
438 	sinp(UART_RX);
439 	sinp(UART_IIR);
440 	sinp(UART_MSR);
441 
442 	/* Set line for power source */
443 	off();
444 
445 	/* Clear registers again to be sure. */
446 	sinp(UART_LSR);
447 	sinp(UART_RX);
448 	sinp(UART_IIR);
449 	sinp(UART_MSR);
450 
451 	switch (type) {
452 	case IR_IRDEO:
453 	case IR_IRDEO_REMOTE:
454 		/* setup port to 7N1 @ 115200 Baud */
455 		/* 7N1+start = 9 bits at 115200 ~ 3 bits at 38kHz */
456 
457 		/* Set DLAB 1. */
458 		soutp(UART_LCR, sinp(UART_LCR) | UART_LCR_DLAB);
459 		/* Set divisor to 1 => 115200 Baud */
460 		soutp(UART_DLM, 0);
461 		soutp(UART_DLL, 1);
462 		/* Set DLAB 0 +  7N1 */
463 		soutp(UART_LCR, UART_LCR_WLEN7);
464 		/* THR interrupt already disabled at this point */
465 		break;
466 	default:
467 		break;
468 	}
469 
470 	return 0;
471 }
472 
473 static void serial_ir_timeout(unsigned long arg)
474 {
475 	DEFINE_IR_RAW_EVENT(ev);
476 
477 	ev.timeout = true;
478 	ev.duration = serial_ir.rcdev->timeout;
479 	ir_raw_event_store_with_filter(serial_ir.rcdev, &ev);
480 	ir_raw_event_handle(serial_ir.rcdev);
481 }
482 
483 /* Needed by serial_ir_probe() */
484 static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
485 			unsigned int count);
486 static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle);
487 static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier);
488 static int serial_ir_open(struct rc_dev *rcdev);
489 static void serial_ir_close(struct rc_dev *rcdev);
490 
491 static int serial_ir_probe(struct platform_device *dev)
492 {
493 	struct rc_dev *rcdev;
494 	int i, nlow, nhigh, result;
495 
496 	rcdev = devm_rc_allocate_device(&dev->dev, RC_DRIVER_IR_RAW);
497 	if (!rcdev)
498 		return -ENOMEM;
499 
500 	if (hardware[type].send_pulse && hardware[type].send_space)
501 		rcdev->tx_ir = serial_ir_tx;
502 	if (hardware[type].set_send_carrier)
503 		rcdev->s_tx_carrier = serial_ir_tx_carrier;
504 	if (hardware[type].set_duty_cycle)
505 		rcdev->s_tx_duty_cycle = serial_ir_tx_duty_cycle;
506 
507 	switch (type) {
508 	case IR_HOMEBREW:
509 		rcdev->device_name = "Serial IR type home-brew";
510 		break;
511 	case IR_IRDEO:
512 		rcdev->device_name = "Serial IR type IRdeo";
513 		break;
514 	case IR_IRDEO_REMOTE:
515 		rcdev->device_name = "Serial IR type IRdeo remote";
516 		break;
517 	case IR_ANIMAX:
518 		rcdev->device_name = "Serial IR type AnimaX";
519 		break;
520 	case IR_IGOR:
521 		rcdev->device_name = "Serial IR type IgorPlug";
522 		break;
523 	}
524 
525 	rcdev->input_phys = KBUILD_MODNAME "/input0";
526 	rcdev->input_id.bustype = BUS_HOST;
527 	rcdev->input_id.vendor = 0x0001;
528 	rcdev->input_id.product = 0x0001;
529 	rcdev->input_id.version = 0x0100;
530 	rcdev->open = serial_ir_open;
531 	rcdev->close = serial_ir_close;
532 	rcdev->dev.parent = &serial_ir.pdev->dev;
533 	rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
534 	rcdev->driver_name = KBUILD_MODNAME;
535 	rcdev->map_name = RC_MAP_RC6_MCE;
536 	rcdev->min_timeout = 1;
537 	rcdev->timeout = IR_DEFAULT_TIMEOUT;
538 	rcdev->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
539 	rcdev->rx_resolution = 250000;
540 
541 	serial_ir.rcdev = rcdev;
542 
543 	setup_timer(&serial_ir.timeout_timer, serial_ir_timeout,
544 		    (unsigned long)&serial_ir);
545 
546 	result = devm_request_irq(&dev->dev, irq, serial_ir_irq_handler,
547 				  share_irq ? IRQF_SHARED : 0,
548 				  KBUILD_MODNAME, &hardware);
549 	if (result < 0) {
550 		if (result == -EBUSY)
551 			dev_err(&dev->dev, "IRQ %d busy\n", irq);
552 		else if (result == -EINVAL)
553 			dev_err(&dev->dev, "Bad irq number or handler\n");
554 		return result;
555 	}
556 
557 	/* Reserve io region. */
558 	if ((iommap &&
559 	     (devm_request_mem_region(&dev->dev, iommap, 8 << ioshift,
560 				      KBUILD_MODNAME) == NULL)) ||
561 	     (!iommap && (devm_request_region(&dev->dev, io, 8,
562 			  KBUILD_MODNAME) == NULL))) {
563 		dev_err(&dev->dev, "port %04x already in use\n", io);
564 		dev_warn(&dev->dev, "use 'setserial /dev/ttySX uart none'\n");
565 		dev_warn(&dev->dev,
566 			 "or compile the serial port driver as module and\n");
567 		dev_warn(&dev->dev, "make sure this module is loaded first\n");
568 		return -EBUSY;
569 	}
570 
571 	result = hardware_init_port();
572 	if (result < 0)
573 		return result;
574 
575 	/* Initialize pulse/space widths */
576 	serial_ir.duty_cycle = 50;
577 	serial_ir.carrier = 38000;
578 
579 	/* If pin is high, then this must be an active low receiver. */
580 	if (sense == -1) {
581 		/* wait 1/2 sec for the power supply */
582 		msleep(500);
583 
584 		/*
585 		 * probe 9 times every 0.04s, collect "votes" for
586 		 * active high/low
587 		 */
588 		nlow = 0;
589 		nhigh = 0;
590 		for (i = 0; i < 9; i++) {
591 			if (sinp(UART_MSR) & hardware[type].signal_pin)
592 				nlow++;
593 			else
594 				nhigh++;
595 			msleep(40);
596 		}
597 		sense = nlow >= nhigh ? 1 : 0;
598 		dev_info(&dev->dev, "auto-detected active %s receiver\n",
599 			 sense ? "low" : "high");
600 	} else
601 		dev_info(&dev->dev, "Manually using active %s receiver\n",
602 			 sense ? "low" : "high");
603 
604 	dev_dbg(&dev->dev, "Interrupt %d, port %04x obtained\n", irq, io);
605 
606 	return devm_rc_register_device(&dev->dev, rcdev);
607 }
608 
609 static int serial_ir_open(struct rc_dev *rcdev)
610 {
611 	unsigned long flags;
612 
613 	/* initialize timestamp */
614 	serial_ir.lastkt = ktime_get();
615 
616 	spin_lock_irqsave(&hardware[type].lock, flags);
617 
618 	/* Set DLAB 0. */
619 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
620 
621 	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
622 
623 	spin_unlock_irqrestore(&hardware[type].lock, flags);
624 
625 	return 0;
626 }
627 
628 static void serial_ir_close(struct rc_dev *rcdev)
629 {
630 	unsigned long flags;
631 
632 	spin_lock_irqsave(&hardware[type].lock, flags);
633 
634 	/* Set DLAB 0. */
635 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
636 
637 	/* First of all, disable all interrupts */
638 	soutp(UART_IER, sinp(UART_IER) &
639 	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
640 	spin_unlock_irqrestore(&hardware[type].lock, flags);
641 }
642 
643 static int serial_ir_tx(struct rc_dev *dev, unsigned int *txbuf,
644 			unsigned int count)
645 {
646 	unsigned long flags;
647 	ktime_t edge;
648 	s64 delta;
649 	int i;
650 
651 	spin_lock_irqsave(&hardware[type].lock, flags);
652 	if (type == IR_IRDEO) {
653 		/* DTR, RTS down */
654 		on();
655 	}
656 
657 	edge = ktime_get();
658 	for (i = 0; i < count; i++) {
659 		if (i % 2)
660 			hardware[type].send_space();
661 		else
662 			hardware[type].send_pulse(txbuf[i], edge);
663 
664 		edge = ktime_add_us(edge, txbuf[i]);
665 		delta = ktime_us_delta(edge, ktime_get());
666 		if (delta > 25) {
667 			spin_unlock_irqrestore(&hardware[type].lock, flags);
668 			usleep_range(delta - 25, delta + 25);
669 			spin_lock_irqsave(&hardware[type].lock, flags);
670 		} else if (delta > 0) {
671 			udelay(delta);
672 		}
673 	}
674 	off();
675 	spin_unlock_irqrestore(&hardware[type].lock, flags);
676 	return count;
677 }
678 
679 static int serial_ir_tx_duty_cycle(struct rc_dev *dev, u32 cycle)
680 {
681 	serial_ir.duty_cycle = cycle;
682 	return 0;
683 }
684 
685 static int serial_ir_tx_carrier(struct rc_dev *dev, u32 carrier)
686 {
687 	if (carrier > 500000 || carrier < 20000)
688 		return -EINVAL;
689 
690 	serial_ir.carrier = carrier;
691 	return 0;
692 }
693 
694 static int serial_ir_suspend(struct platform_device *dev,
695 			     pm_message_t state)
696 {
697 	/* Set DLAB 0. */
698 	soutp(UART_LCR, sinp(UART_LCR) & (~UART_LCR_DLAB));
699 
700 	/* Disable all interrupts */
701 	soutp(UART_IER, sinp(UART_IER) &
702 	      (~(UART_IER_MSI | UART_IER_RLSI | UART_IER_THRI | UART_IER_RDI)));
703 
704 	/* Clear registers. */
705 	sinp(UART_LSR);
706 	sinp(UART_RX);
707 	sinp(UART_IIR);
708 	sinp(UART_MSR);
709 
710 	return 0;
711 }
712 
713 static int serial_ir_resume(struct platform_device *dev)
714 {
715 	unsigned long flags;
716 	int result;
717 
718 	result = hardware_init_port();
719 	if (result < 0)
720 		return result;
721 
722 	spin_lock_irqsave(&hardware[type].lock, flags);
723 	/* Enable Interrupt */
724 	serial_ir.lastkt = ktime_get();
725 	soutp(UART_IER, sinp(UART_IER) | UART_IER_MSI);
726 	off();
727 
728 	spin_unlock_irqrestore(&hardware[type].lock, flags);
729 
730 	return 0;
731 }
732 
733 static struct platform_driver serial_ir_driver = {
734 	.probe		= serial_ir_probe,
735 	.suspend	= serial_ir_suspend,
736 	.resume		= serial_ir_resume,
737 	.driver		= {
738 		.name	= "serial_ir",
739 	},
740 };
741 
742 static int __init serial_ir_init(void)
743 {
744 	int result;
745 
746 	result = platform_driver_register(&serial_ir_driver);
747 	if (result)
748 		return result;
749 
750 	serial_ir.pdev = platform_device_alloc("serial_ir", 0);
751 	if (!serial_ir.pdev) {
752 		result = -ENOMEM;
753 		goto exit_driver_unregister;
754 	}
755 
756 	result = platform_device_add(serial_ir.pdev);
757 	if (result)
758 		goto exit_device_put;
759 
760 	return 0;
761 
762 exit_device_put:
763 	platform_device_put(serial_ir.pdev);
764 exit_driver_unregister:
765 	platform_driver_unregister(&serial_ir_driver);
766 	return result;
767 }
768 
769 static void serial_ir_exit(void)
770 {
771 	platform_device_unregister(serial_ir.pdev);
772 	platform_driver_unregister(&serial_ir_driver);
773 }
774 
775 static int __init serial_ir_init_module(void)
776 {
777 	int result;
778 
779 	switch (type) {
780 	case IR_HOMEBREW:
781 	case IR_IRDEO:
782 	case IR_IRDEO_REMOTE:
783 	case IR_ANIMAX:
784 	case IR_IGOR:
785 		/* if nothing specified, use ttyS0/com1 and irq 4 */
786 		io = io ? io : 0x3f8;
787 		irq = irq ? irq : 4;
788 		break;
789 	default:
790 		return -EINVAL;
791 	}
792 	if (!softcarrier) {
793 		switch (type) {
794 		case IR_HOMEBREW:
795 		case IR_IGOR:
796 			hardware[type].set_send_carrier = false;
797 			hardware[type].set_duty_cycle = false;
798 			break;
799 		}
800 	}
801 
802 	/* make sure sense is either -1, 0, or 1 */
803 	if (sense != -1)
804 		sense = !!sense;
805 
806 	result = serial_ir_init();
807 	if (!result)
808 		return 0;
809 
810 	serial_ir_exit();
811 	return result;
812 }
813 
814 static void __exit serial_ir_exit_module(void)
815 {
816 	del_timer_sync(&serial_ir.timeout_timer);
817 	serial_ir_exit();
818 }
819 
820 module_init(serial_ir_init_module);
821 module_exit(serial_ir_exit_module);
822 
823 MODULE_DESCRIPTION("Infra-red receiver driver for serial ports.");
824 MODULE_AUTHOR("Ralph Metzler, Trent Piepho, Ben Pfaff, Christoph Bartelmus, Andrei Tanas");
825 MODULE_LICENSE("GPL");
826 
827 module_param(type, int, 0444);
828 MODULE_PARM_DESC(type, "Hardware type (0 = home-brew, 1 = IRdeo, 2 = IRdeo Remote, 3 = AnimaX, 4 = IgorPlug");
829 
830 module_param_hw(io, int, ioport, 0444);
831 MODULE_PARM_DESC(io, "I/O address base (0x3f8 or 0x2f8)");
832 
833 /* some architectures (e.g. intel xscale) have memory mapped registers */
834 module_param_hw(iommap, ulong, other, 0444);
835 MODULE_PARM_DESC(iommap, "physical base for memory mapped I/O (0 = no memory mapped io)");
836 
837 /*
838  * some architectures (e.g. intel xscale) align the 8bit serial registers
839  * on 32bit word boundaries.
840  * See linux-kernel/drivers/tty/serial/8250/8250.c serial_in()/out()
841  */
842 module_param_hw(ioshift, int, other, 0444);
843 MODULE_PARM_DESC(ioshift, "shift I/O register offset (0 = no shift)");
844 
845 module_param_hw(irq, int, irq, 0444);
846 MODULE_PARM_DESC(irq, "Interrupt (4 or 3)");
847 
848 module_param_hw(share_irq, bool, other, 0444);
849 MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
850 
851 module_param(sense, int, 0444);
852 MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit (0 = active high, 1 = active low )");
853 
854 #ifdef CONFIG_IR_SERIAL_TRANSMITTER
855 module_param(txsense, bool, 0444);
856 MODULE_PARM_DESC(txsense, "Sense of transmitter circuit (0 = active high, 1 = active low )");
857 #endif
858 
859 module_param(softcarrier, bool, 0444);
860 MODULE_PARM_DESC(softcarrier, "Software carrier (0 = off, 1 = on, default on)");
861